Increasing demands are being placed on cellular wireless networks to provide information regarding the locations of mobile stations. Accurate location information can be important when a mobile station is making an emergency services call, such as a 9-1-1 call. However, mobile stations are also being used to provide location-based applications to subscribers, such as providing driving directions or identifying nearby business. The Global Positioning System (GPS) is often used to determine the location of a mobile station in response to the user making an emergency services call or invoking a location-based application.
However, location information can also be used for network planning purposes. For example, it may be useful for wireless network operators to understand the geographic distribution of mobile stations at different times of the day. Given the large number of mobile stations involved, it may not be feasible to rely on GPS location fixes. Accordingly, there continues to be a need to find ways of estimating the locations of mobile stations.